Article supporting rack for plating



Sept 13, 1938. A. PEARSON ARTICLE SUPPORTING RACK FOR PLATING' FiledOct. 3, I936 fill filial? A. PARso/v #Q Mm ATTORNEY Patented Sept. 13,1938 ARTICLE SUPPORTKNG RACK FOR PLATENG Albert Pearson, WesternSprings, 111., assignor to Western Electric Company, Incorporated, NewYork, N. Y, a corporation of New York Application October 3,

"' 3 Claims.

This invention relates to article supporting racks, and moreparticularly to racks for plating sheet metal.

Certain articles require a localized coating and it is often desirableto restrict the covered areas, particularly when costly coatingmaterials such as gold or other noble metals are employed. In some casesit is desirable to coat one side of a metal sheet and subsequently toform the composite sheet into the article.

. An object of this invention is to provide an improved method and rackfor use in the application of a localized coating on sheet material.

In accordance with. one embodiment of the invention, a rack is providedfor supporting a metal strip in a plating apparatus and localizing thedeposit of metal on one face thereof. The

rack comprises'a continuous surface having an oval section on which thestrip is wound spirally and clamped to prevent contact between theelectrolyte and the under surface of the strip. Plating current'isconducted to the strip through a contact bar along the top of the rack.

A complete understanding of the invention may be had from the followingdetailed description taken in conjunction with the appended drawing inwhich the single figure is a perspective view of a plating rackembodying the invention.

For convenience and economy a plating rack embodying the invention isadapted for use in a conventional electroplating apparatus in which therack is suspended from a. his bar ID in an electrolyte (not shown).

As shown in the drawing, a supporting frame made of wood, fibre, orother insulating material comprises a main rectangular vertical framemember H which has a rounded bottom portion I2. A plurality of crossmembers orarms extend horizontally and symmetrically 4 from the twofaces of the main member at right angles thereto. A central cross arm I3is supported at the approximate middle of each face of the main member.Two upper cross arms l4 and two lower cross arms l5 mounted neartherespective endsof the main member are relatively shorter than thecentral arms so that the ends of the cross arms and main memberdescribe-an approximate oval.

Mounted along the full length of the top ofthe main frame member isahalf round rod or bar l6 of brass, copper, or other conducting material.

1936, Serial No. 103,872

A bracket H is welded to each end of the rod and fastened to the mainframe member with screws.

A continuous sheet is of fibre, rubber or other insulating material,equal in width to the length of the conductor rod is mounted around theouter ends of the frame cross arms and secured thereto with countersunkscrews it. The two ends of the sheet abut against the portions of therod projecting beyond the face of the main frame member and are anchoredsecurely with screws (notshown) to the main member. The projectingportions of the half round rod are made equal to the thickness of thesheet to insure a smooth continuous surface at the junctures betweenthese members. At the bottom of the rack, the sheet nests against therounded portion of the main frame member and the rod and sheet thuscollectively provide a continuous, smooth surface for receiving thestrip material.

To each end of the half round rod a formed arm 20 of brass, copper orother conducting material is secured by welding, brazing, or othersuitable method, such as threading the arm into the rod to provide agood electrical contact for conducting plating current to the rod. Thetwo arms extend upwards and are each provided with a hook'2l forengaging the bus bar of the plating apparatus and a handle 22 forconvenient transportation of the rack.

At the upper left corner of the rack just below the conductor rodis aclamp 23 threaded in the main frame member and provided with an enlargedhead of rubber or other non-conducting strip is then wound spirally onthe surface of the rack and the conductor rod under suflicient tensionto insure close contact between the underside of the strip and the racksurface. ing end of the strip is fastened securely with the right handclamp to hold the strip and rack in proper relationship. Circulation ofthe electrolyte against the inner surface 'of the strip is prevented bycontact with the rack surface and the deposit of metal on that area isaccordingly prevented.

Plating current is introduced to the strip through contact with the halfround rod, whichis connected to the bus bar through the supporting arms.Introduction of current to the uniformly spaced intervals of' the stripin contact The terminat- I with the rod facilitates theelectrodeposition of a uni orm coating on the strip surface.

In the plating operation, vertically arranged anodes (not shown) arepositioned on opposite careful consideration is directed to the frame.

members which are preferably constructed to form the strip supportingsurface into an approximately oval section so that all portions of thestrip will be in close contact with the convex surface of the rack. Forrelatively thick material it may be necessary to form the rack morenearly cylindrical in shape to insure continuous contact between thestrip and rack? surface. However, a rack having an elongated axis ispreferred because this construction presents the strip more uniformly tothe plating anode which assists in control of coating thickness and alsopermits a greater number of racks to be placed in a tankof given length.

The surface of the rack can be made of hard rubber or phenol fibre andin some cases may be faced with soft rubber, depending on the size andcomposition of the strip material. For plating thin brass strip, hardrubber approximately is" thick was usei satisfactorily and the thinstrip was retained in sufficiently close contact with the rack surfacewithout difficulty. For thicker strip or material which does not distorteasily a soft rubber facing into which the material can be imbedded maybe required. Durable, non-conducting materials are employed for theframe, strip supporting sheet and clamps to prevent the deposit of metalon the rack members and to reduce maintenance and repair costs.

A rack of this general description is also suitable for supporting stripmaterial during coating processes other than electroplating, such aspaint or varnish spraying, in cases where it is desirable to restrictthe coating to one side of the strip.

Other modifications of the specific structure described herein can bemade to accommodate various requirements, and it is to be understoodthat the invention is limited only by the scope of the appended claims.

What is claimed is:

1. A plating rack for metal strip, comprising a frame of non-conductingmaterial, an elongated member made of conducting material mounted on theframe, a sheet of insulating material mounted on the frame with its endsabutting against the conducting member for receiving the metal strip, aclamp mounted on the frame for securing one end of the strip, a secondclamp on the frame for engaging the other end of the strip and holdingthe strip in close contact with the insulating sheet and the conductingmember, and means for conducting plating current to the conductingmember.

2. A plating rack for metal strip, comprising a frame of non-conductingmaterial having a main vertical member and a plurality of cross membersextending therefrom, a bar of conducting material secured to the top ofthe vertical member, a continuous sheet of insulating material securedto the end of the frame cross members with its ends abutting theconducting bar, and an arm of conducting material extending from the barfor conducting plating current thereto.

3. A rack for plating metal strip, comprising a frame having a centralmember and a plurality of cross arms projecting therefrom, a bar ofconducting materlal having a semi-circular crosssection secured to thetop of the central frame member with portions ofthe bar diameterextending beyond both faces of the frame member, a continuous sheet ofinsulating material secured to the ends of the frame cross arms with itsends abutting the projecting portions of the con-' ductor bar forsupporting the strip, a formed arm secured to the bar for conductingplating current thereto, and a plurality of clamps for securing thestrip tov the supporting surface of the rack.

ALBERT PEARSON.

